Genosensor to detect cholera

doi:10.1038/nindia.2016.2 Published online 8 January 2016

Researchers have fabricated an ultrasensitive genosensor for the detection of the water borne virulent bacterium Vibrio cholerae which causes cholera. The label free photoluminescence (PL) based genosensor has the potential for application in clinical diagnosis of cholera.

Cholera is caused by ingestion of contaminated water and food. Conventional cholera diagnosis tests — polymerase chain reaction (PCR), biochemical reactions, immunological test, and microscopic examination of cultured bacterium — take from about 2-3 days to a week. The disease may spread and become fatal during this time. Besides, false positivity and cross-reactions have also been reported in PCR, particularly in commercially viable assays.

The researchers set out to device a highly specific, rapid and sensitive diagnosis test to deal with the infection at primary stage. They developed an optical DNA biosensing device which can efficiently detect V. cholerae. This nanostructured magnesium oxide (nMgO)-based photoluminescence genosensor exhibited higher sensitivity (1.306 emi/ng) and lower detection limit of 3.133 ng/µL.

The researchers say that the probe DNA (pDNA) conjugated with the nMgO could be used for the development of a new generation of in vivo biomedical sensors, biochips and compact point-of-care biomedical devices for detection of other virulent bacterial and viral infections.